Central WWTP Headworks and Primary Clarifiers Improvements

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OWNER
City of Dallas

ENGINEER
Garver

COMPLETION DATE
June 2026

AMOUNT
51,854,806

Project Details

This project involved extensive construction and rehabilitation of treatment processes to a century old facility with a capacity of over 300MGD.  The work under this project involved:

  1. Dallas Headworks Rehabilitation – Demolish existing concentrators and classifiers; Provide drum screen, grit hopper, and associated piping and appurtenances; Provide new grit pumps, cyclone concentrators, classifiers, and associated piping and appurtenances (Bid Alternate 2).

 

  1. White Rock Headworks Rehabilitation – Demolish existing concentrators and classifiers; Replace 6-inch grit slurry pipe with 4-inch pipe and long radius bends; Replace and right-size NPW line; Install heat trace and insulation; Provide new or rehabilitated pumps, cyclone concentrators, classifiers, and associated piping and appurtenances.

 

  1. Primary Clarifiers C and D Influent Pipeline Rehabilitation – Install CIPP the full length of both influent pipelines to Clarifiers C and D; Install CFRP in both influent pipelines to Clarifiers C and D where there is significant deterioration.

 

  1. Influent Splitter Box – Install new influent splitter box structure, including launder troughs, weirs, slide gates, walkway, autosampler, and safety railing.

 

  1. Primary Clarifiers – Demolish existing primary clarifiers A and B and below grade Imhoff tanks as directed on Drawings; Install new primary clarifiers A, B, and E with spiral rake mechanisms, EDI, flocculating feedwell, walkway, dual sided weirs and launders, scum beaches and sprayers, sludge hopper, and a covered effluent channel and box; Install attached scum pump stations on each clarifier.

 

  1. Effluent Flow Control Structure – Install new primary effluent flow control structure, including slide gates, flow meters, valves, sump pumps, launder and weirs, grating, and safety railing.

 

  1. Primary Sludge Pump Station – Install new sludge pump station and electrical building; Install cleanouts, pumps, valves and appurtenances, HVAC, and associated electrical equipment.

 

  1. Primary Sludge Meter Vault – Demolish existing sludge meter vault; Install new sludge meter vault; Provide new sump pumps, flow meters, and valves.

 

  1. Hazardous-Materials Building – Relocate the building on-site